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I have an ubuntu vps running that has about 300MB of memory, of which only 20% or less is free right now ...
My question is, how can I figure out what particular program I'm running that is causing it to swap so much?

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up vote 7 down vote accepted

To find out the amount of swap space used by every process, run top (not htop), press 'f' to select columns (f for fields) to display, press 'p' to add swap to display, press 'o' to sort the table (o for order by) and press 'p' again to order by swap usage.

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That was exactly what i needed ... If only i could figure out how to accomplish this in htop. – trustfundbaby Apr 14 '10 at 7:48
Also, to sort I had to use shift+o and shift+p – trustfundbaby Apr 14 '10 at 7:54
In htop, you use the "F" Keys to sort. See the line at the very bottom of the screen. – Antoine Benkemoun Apr 15 '10 at 7:09

start with running


and pressing M [ shift+m ].

you will get process list sorted by mem consumption.

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was already using htop. – trustfundbaby Apr 14 '10 at 0:37

smem is a bit harder to use than top, but offers good information. You could start with with sudo smem -s uss -r -k which will output:

  PID User     Command                         Swap      USS      PSS      RSS 
12345 spam     /usr/lib/jvm/java-6-sun/bin        0   620.9M        0   626.5M 
98765 eggs     /usr/bin/java -Xmx1500m -XX        0   544.2M        0   549.9M 

You might also want to check out this article, which explains the difference between RSS, PSS and USS.

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Another option is htop, which has better output in some cases.

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I'm already using htop ... can't figure out how to see the amount of swap each process is using. – trustfundbaby Apr 14 '10 at 0:36
@user37899 You should at least check that it works, if you don't say exactly how, before suggesting a solution – Prof. Moriarty Apr 14 '10 at 8:17

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